Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Planet Under Stress Chapter 31 Copyright © McGraw-Hill Companies Permission required for reproduction or display

Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Outline Pollution  Biological Magnification  Acid Rain Ozone Hole Greenhouse Effect Reducing Pollution Preserving Non-Replaceable Resources Curbing Population Growth

Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Pollution Air Pollution  Major problem in world’s cities. - Industry and / or automobiles. Chemical Pollution  Growth of heavy industry and overly casual attitude in industrialized countries.  Agricultural Chemicals - Fertilizers, Pesticides, Herbicides.  Biological Magnification

Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Biological Magnification of DDT

Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Acid Rain In mid-1950’s, power plants began to use tall smokestacks to release sulfur into winds where it would be dispersed and diluted.  Simply exported problems - “Normal” rain pH is about 5.6.  Some samples in US measured at 4.3.  Solution is to capture and remove emissions prior to release. - Expensive - Polluter and Recipient loacated far apart.

Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Ozone Hole Realized in 1975 that the ozone shield was disintegrating.  Culprit was chlorofluorocarbons (CFCs). - Invented in 1920’s and used extensively as coolants and aerosol dispensers.  Very stable, thus accumulate over time.  Catalyze ozone (O 3 ) into diatomic oxygen (O 2 ) without being used up.

Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Ozone Hole Estimated 1% drop in ozone content leads to 6% increase in incidents of skin cancer.

Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Greenhouse Effect For over 150 years, our industrial society has been fueled by cheap energy, much of it obtained by burning fossil fuels.  Produced carbon dioxide. - Allows radiant energy from sun into the atmosphere, but traps heat radiation.  Greenhouse Effect  Global warming thought to be occurring due to accumulation of greenhouse gases.

Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Greenhouse Effect

Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Reducing Pollution Human activities are placing a severe stress on the global ecosystem.  Failure of our economy to set a proper price on environmental health. - Indirect costs of pollution are not usually taken into account.  Antipollution Laws  Pollution Taxes

Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Finding Other Sources of Energy In theory, nuclear power can provide plentiful, cheap energy. But several problems are also presented and must be overcome:  Safe Operation  Waste Disposal  Security

Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Preserving Non-Replaceable Resources Topsoil  Lost at rate of centimeters per decade. - US has lost one-quarter of topsoil since Groundwater  Seeped into underground reservoir slowly over last ice age 12,000 years ago.

Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Preserving Non-Replaceable Resources Biodiversity  Over last 20 years, about half world’s tropical rain forests have been either burned for pasture or cut for timber.  Pacific Northwest Old-Growth Forests are being cut at a phenomenal rate. - Potential benefits lost  Food Source  Medicinal Drugs

Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Curbing Population Growth Since at least 1650, average human birthrate has remained steady at about 30 births per 1,000 people.  Death rate has steadily declined to an estimated 9 deaths per 1,000 people. World population passed 6 billion in  Massive movement toward urban centers.  Most future growth will be in less- developed countries.

Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Human Population Growth Curve Copyright © McGraw-Hill Companies Permission required for reproduction or display

Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Curbing Population Growth Population Growth Rate Declining  In 1994 the world population growth rate and average number of children per woman were smaller than expected. - United Nations attributes decline to increased family planning efforts and increased economic power and social status of women.

Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Curbing Population Growth Slowing population growth will help sustain resources, but per capita consumption must also be addressed.  Wealthiest 20% of world population accounts for 80% of world’s resource consumption. - Poorest 20% is responsible for only 1.3% of consumption.

Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies What You Have To Contribute Environmental Problem Solving:  Assessment  Risk Analysis  Public Education  Political Education  Follow-Through

Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Review Pollution  Biological Magnification  Acid Rain Ozone Hole Greenhouse Effect Reducing Pollution Preserving Non-Replaceable Resources Curbing Population Growth

Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Copyright © McGraw-Hill Companies Permission required for reproduction or display